Paul,
I like your switch arrangement except for one detail: I would reposition the ICO buttons so that the middle one is further inboard than the other 2. The reason for this is that, in a rally, you often must "bump" your ICO up or down to reset your mileage to some point in the roadbook. To be safe, you want to just glance at your ICO at that point and make a mental note of how many tenths (or hundredths) you need to bump up or down. Then, when you are back looking at the trail and not your ICO, you can reach over with your thumb to bump either the up or down ICO button the correct number of bumps to reset your ICO. In the current configuration, you must reach over the "big" ICO button to press the up or down bump buttons. Sometimes, especially when you are not looking at your ICO (as you shouldn't be), you can accidentally hit the big button and toggle from odometer to speedometer. Then your carefully calculated up or down bumps will do nothing to the odometer and your reset will not have worked. Now your odometer is not set accurately to the roadbook and you may miss the next turn or danger. Check out some of the factory bikes, many of them have repositioned the ICO buttons this way. I think that ICO has the stock switches configured wrong for rallying, but maybe they are correct for Enduro, I don't know.
fun fun
Charlie